A machine to machine (M2M) technology is an integration of wireless communication and information technologies, and indicates that communication may be directly performed between a machine and another machine without manual intervention. M2M is rich in types of applications, including automatic instruments, remote monitoring, industrial security, ship automation, payment systems, vehicle remote control, and the like.
The M2M exists in three manners, including machine to machine, machine to mobile phone, and mobile phone to machine. In the M2M, an M2M device may access a network through a long distance connection technology and a short distance connection technology. The involved long distance connection technology includes wireless access type technologies such as a global system for mobile communications (GSM), a general packet radio service (GPRS), and a universal mobile telecommunications system (UMTS). The short distance connection technology includes 802.11b/g, blue tooth (Blue Tooth), Zigbee (Zigbee), a radio frequency identification (RFID) technology and an ultra wideband (UWB) technology. Definitely, other technologies that may be used to support M2M communication are included The M2M communication may also be referred to as machine type communication (MTC), and the M2M device may also be referred to as an MTC device.
In the prior art, a base station builds a common physical layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer and a media access control (MAC) layer for a same group of MTC devices. After establishing a common bearer for the same group of MTC devices, each MTC device has its own separate key, keys of the MTC devices are different from each other, and a PDU unit interacting between the base station and an MTC device needs to carry an MTC device identifier to search for a corresponding key according to the identifier. Therefore, at the base station, it is required to maintain respective keys for MTC devices in the same group, which increases operation complexity of the base station, so that the number of keys that need to be maintained and managed by the base station is excessive, thereby affecting the performance of the base station.